[R] replacing elements of vector through elements of another vector

[Marcus Mund]

Dear Marc and David,

thank you so much for casting off my blinkers - it works!

Marcus


Am 27.07.2011 17:52, schrieb David Winsemius:
> On Jul 27, 2011, at 10:52 AM, Marcus Mund wrote:
> 
>> Hello everybody,
>>
>> I hope this question is not too silly but I'm almost going crazy about
>> that and could not find a solution.
>>
>> I have two variables, say A and B and I would like to combine them in C.
>> In particular I want a C-value of B when B is not NA and the A value in
>> case that B is NA:
>>
>> A   B   C
>> 2   NA  2
>> 3   4   4
>> NA  3   3
>> 4   1   1
>> 2   NA  2
>> 1   4   4
>> NA  NA  NA
>> 5   3   3
>> 4   1   1
>>
>> I tried something like:
>>
>> C <- B #assigning variable B to variable C
>> C[is.na(B) & A >= 0] <- A #using value of A in case that B is na
> 
> Just use:
> 
>  C[is.na(B) ] <- A[is.na(B) ]
> 
> # doesn't matter what A is. Or if it does, then use same logical vecot
> index on both sides
> 
> You need to have is.na(B) on both sides to get the vector assignments to
> match up. That is what the error message is telling you.
> 
>>
>> but this results in an error message about the unequal length of the
>> replacement and what has to be replaced...
>>
>> I guess I am too deep in the problem to see the (probably) easy
>> solution, hence any hints and advices are appreciated.
>>
>> Thank you very much!
>>
>> Marcus
>> -- 
>> Dipl.-Psych. Marcus Mund
>> Friedrich-Schiller-University Jena
>> Institute for Psychology
>> Department of Personality Psychology and Psychological Assessment
>> Humboldtstraße 11/Raum 111
>> 07743 Jena, Germany
>>
>> Tel.: +49 3641/9-45 960
>> Mail: marcus.mund at uni-jena.de
>> Fingerprint: 6B15F90EA7752D9E327A055427F4F5DC255188C4
>>
>> ______________________________________________
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>> and provide commented, minimal, self-contained, reproducible code.
> 
> David Winsemius, MD
> West Hartford, CT

-- 
Dipl.-Psych. Marcus Mund
Friedrich-Schiller-University Jena
Institute of Psychology
Department of Personality Psychology and Psychological Assessment
Humboldtstraße 11
07743 Jena, Germany

Phone: +49 3641/9-45 960
Mail: marcus.mund at uni-jena.de
Fingerprint: 6B15F90EA7752D9E327A055427F4F5DC255188C4